The broadband wireless access technology refers to broadband access using radio resources, and channels are critical to the broadband wireless access technology. In the present application, the channel is a general terminology, which refers to a communication system resource such as a physical frequency band or a virtual link resource. For example, a time division multiplex band may generate multiple virtual channels, and different CDMA code words correspond to different CDMA channels.
For a base station (BS), the neighbor BSs of the BS are BSs that share a common coverage area with the BS, and in the common coverage area there are one or more effective terminals. For example, for a BS A, a BS B is a neighbor BS. Then, for the BS B, the BS A is also a neighbor BS. In other words, a neighborhood relationship exists between the BS A and B.
All the BSs in the network share limited resources, no BSs can occupy the resources in the network freely without any constraints, and the resources shall be allocated by plan or negotiation. As for a network section without feasible channel plan or using the license-exempt band (LE band) in the network, a problem will arise that multiple BSs occupy the same channel simultaneously, and therefore interference between the BSs is inevitable. For a large scale network, the channel negotiation between the neighbor BSs is critical to the utilization efficiency of the resources, and therefore the performance of the BSs and the network is affected. Various methods of channel negotiation between the neighbor BSs in the prior art are listed as follow.
Method 1: A network planning is performed to allocate channels statically for the BSs so as to ensure that the BSs in the common coverage area occupy different channels. However, the method does not support a dynamic allocation. When the topology of the network changes, the allocation needs to be re-planned, so this method has a low efficiency.
Method 2: A group of BSs having the neighborhood relationship are defined as one community, and the channels are allocated to each BS in the community through a particular algorithm, such as greedy algorithm so as to ensure an optimal performance by using the minimum number of channels. The method may be implemented in two ways, namely, a centralized mode and a distributed mode. In the centralized mode, a BS is designated to perform channel distribution computation, and then the other BSs are ordered to switch to a target channel according to the computation result. In the distributed mode, all the BSs in the community compute the target channels of the BSs simultaneously when being informed of the topology change of the network, and each of the BSs performs the switch at the same time after computing the target channel of the BS.
When new BSs join in the community, distribution computation needs to be performed in the whole community again, and most of the BSs in the community will switch channel. The above process increases terminal cost, and is conflict with current protocols.